ENERGY RELAXATION OF HOT-ELECTRONS IN A QUANTUM-WELL - CONFINED OPTICAL AND ACOUSTIC-PHONON EFFECTS

Energy-loss rates of hot electrons are calculated for a semiconductor quantum well (QW) of the GaAs/AlGaAs prototype. Couplings with acousti c phonons (AP) and with confined polar-optical phonons (OP) are consid ered. Hot electrons are assumed in internal equilibrium at a temperatu re T-e (the temperature model). Comparison with previous calculations of other authors shows that OP confinement with the proper dispersion relation is of utmost importance for the correct interpretation of ene rgy-loss rates in the temperature range of 25 to 100 K. In the lower t emperature regime the coupling with AP cannot be neglected. Thus reaso nable agreement with experimental data is obtained even within the rel atively simple model for the calculation when both mechanisms are take n into account. Other effects (hot phonons, etc.) are not considered a nd also no fitting parameters of any kind are introduced.